1. Field of the Invention
The present invention relates to keyed-cylinder locks assemblies and, more particularly, to reset cradle for recovering a blown cylinder of a lock assembly of a type employing a quick rekey cylinder.
2. Description of the Background
There is a commercial need to provide interchangeable key-access security so that owners/operators of a premises do not need to replace the lock cylinders every time for example, that tenants change or a tenant key is lost or stolen. This situation is especially acute in multiple-unit buildings such as apartments and office buildings.
When rekeying a cylinder using a traditional cylinder design, the user is required to remove the cylinder plug from the cylinder body and replace the appropriate pins so that a new key can be used to unlock the cylinder. This typically requires the user to remove the cylinder mechanism from the lockset and then disassemble the cylinder to some degree to remove the plug and replace the pins. This requires a working knowledge of the lockset and cylinder mechanism and is usually only performed by locksmiths or trained professionals. Additionally, the process usually employs special tools and requires the user to have access to pinning kits to interchange pins and replace components that can get lost or damaged in the rekeying process. Finally, professionals using appropriate tools can easily pick traditional cylinders.
Electronic key systems now exist to allow an owner to selectively program various key codes, but these systems are cost prohibitive for many business and residential applications.
There have, however, been a few prior efforts to develop a mechanical controlled-access lock. For example, pin tumbler locks which may be rekeyed without removing the tumblers, and therefore rekeyed without a locksmith, are shown in U.S. Pat. No. 1,565,556 of Fremon, issued Dec. 15, 1925, and U.S. Pat. No. 2,603,081 to Pelle, issued Jul. 15, 1952.
U.S. Pat. No. 6,862,909 to Armstrong et al. shows rekeyable lock cylinder and rekeying tool. FIG. 1 illustrates this rekeyable lock cylinder, which comprises a lock cylinder 10, a lock cylinder body 12, and a plug assembly 14. The plug assembly 14 includes a plug body 40, a carrier sub-assembly 42 and a plurality of spring-loaded pins 38, 113. The plug body 40 includes a plug face 44, a keyway opening 52, a rekeying tool opening 54 and a pair of channels 56 extending radially outwardly for receiving anti-drilling ball bearings 60. The carrier sub-assembly 42 includes a carrier 90, a plurality of racks 92, a spring catch 96, a spring-loaded locking bar 94, and a return spring 98. The carrier 90 and the plug body 40 combine to form a cylinder that fits inside the lock cylinder body 12.
To rekey the lock cylinder 10, a valid key is inserted into the keyway and is rotated approximately 90 degrees counterclockwise from the home position. A paperclip or other pointed device is inserted into the rekeying tool opening 54 and is pushed against the carrier 90 to move the carrier 90 parallel to the longitudinal axis of the lock cylinder 10 into a learn mode. The valid key is removed and a second valid key is inserted and rotated clockwise. The carrier 90 is biased toward the plug face 44 by the return spring 98, causing the racks 92 to re-engage the pins 113. At this point, the lock cylinder 10 is keyed to the second valid key and the first valid key no longer operates the lock cylinder 10. The lock cylinder 10 can be rekeyed further as desired.
One problem with the foregoing rekeyable cylinder is that if the second valid key is not fully inserted during the rekeying process, the pins will not be set to conform to the second valid key, resulting in a “blown cylinder.” To aid in recovering a lock cylinder from a blown condition, a manual reset procedure was developed to conform to a profile of a new key, without removing the plug assembly from the cylinder body.
First, with the lock cylinder exposed, a rekeying tool 310 is inserted into the cylinder body 12 to manually position the racks 92 and the pins 113 to release the locking bar 94.
Next, a bracing tool (a simple pin) is used to depress the locking bar 94 and allow the plug body to rotate in the cylinder body to the rekeying position.
Next, the plug 40 is rotated with respect to the cylinder body 12 by 90 degrees. This rotation moves the locking bar 94 into a recess inside the cylinder body 12, which releases the locking bar 94, allowing learn tool 200 to be inserted.
Finally, the learn tool 200 is inserted into the keyslot and this configures the lock cylinder to the learn mode. Once in the learn mode, the rekeying tool 310 and bracing tool are removed and a valid key is inserted in the keyway of the plug assembly. As the new key is inserted, the pins can ride up and down the ramps of the key. Once the key is fully inserted, the pin heights can correlate to the new key. Once the key is rotated to bring the plug 40 to the home position, the racks 92 are then re-engaged with the pins 113, and at this point the lock cylinder 10 is keyed to the new key and any previously valid key no longer operates the lock cylinder 10.
Thus, via the manual reset tool 310, without requiring a valid key, the lock assembly can be placed into a learn mode, in which it can read and conform to a profile of a new key, without removing the plug assembly from the cylinder body.
One difficulty with such manual reset tool 310 is the need for some manual dexterity in handling the lock cylinder, the reset tool assembly, and all associated components of the reset tool that needs to be operated simultaneously (first the rekeying tool 310, then the bracing tool, then cylinder plug 40 rotation, then insertion of the learn tool 200). Another difficulty with such reset tool is the relatively high number of operations that need to be performed in the right sequential order. Such reset tool doesn't have a robust means to prevent someone from performing operations in an incorrect order. Due to these difficulties, proper training needs to be conducted for the user to operate the product.
It would be greatly advantageous to provide a reset cradle with integral components that automatically positions the lock cylinder, inserts a rekeying tool, then a bracing tool, then rotates the cylinder plug 40 to allow insertion of the learn tool 200, all in proper sequence.